Cable and wire covering cutter



March 9 J; WQPAIFIQKS 2,875,516

CABLE AND WIRE COVERING CUTTER Filgd Dec. 18. 1956 firome W. Ru'ks,

. INVENTOR.

11/ brag United States Patent Qflice 2.8 5. 16 ,"Paitnte'd' Mar. 3, 95's CABLE AND WIRE-COVERING cUTrER Jerome W. Parks, Balboa Island, Calif., assignor to Microdot Inc., South Pasadena, 'Calif., a corporation of California Application December, 18, 1956, Serial No. 629,148

' 4 Claims. or. 3 -91 The present invention relates generally to a hand tool,

and is more particularly concerned with a device for cutting the outer layers or coverings of extremely fine insulated wire or cable, the device being especially adapted for cutting the insulation and conducting sheath of coaxial cables.

, .--;In many operations utilizing extremely line coaxial I the cutter blade may hemicropositioned with extreme accuracy. A still further object is to provide in acutter of' this character a construction whichwill= successfully and "accurately-lwork on =a wide range of cable sizes, with .a

minimum ofadjustment, and which will be compact in construction and easily operable by-hand.

.- Another object is to provide a smallhand operated Q cutter in which the cable may be carried. towards and away from the cutting position, so as to permit easy insertionmnd removal ,of thegcableinto; the ,cutter, and wherein the,entire device and cable maybe relatively rotated about the longitudinahaxis ofthe' cable to cut the insulation and any other coverings throughout their circumference.

Still another object is to provide a unique cutting edge which is operatively associated with an anvil which is so constructed that it will center the cable and position it accurately with respect to the cutting edge of the device, irrespective of the size of the cable, and thus assure a concentric cut. 7

Further objects of the invention 'will be brought out in'the'folldwing part of the-specification, wh'er'eirii'detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.

Referring to the accompanying drawings, which are forillustrative purposes only:

Fig. 1 is a side elevational view of a cable covering cutter embodying the features of the present invention;

Fig. 2 is an edge view of the same, showing the handle by which the cutter may be rotated around the cable to complete the cutting operation;

Fig. 3 is an opposite side elevational view of the cutter;

Fig. 4 is a fragmentary view as seen substantially from line 4-4 of Fig. 1, and showing the cooperative relationship of the cable supporting bushing;

Fig. 5 is a sectional view through the cutter, taken substantially on line 5-5 of Fig. 2, and showing the details of the blade adjusting support and the position of the cable supporting bushing during a cutting operation;

Fig. 6 is an enlarged fragmentary sectional view taken substantially on line 6-6 of Fig. 5, and showing sche ,matically the manner in which the portions of the cable ,are upheld and maintained straight during the cutting operation; and I I Fig.7 is a view similar to Fig.5,but showing the cable supporting bushing as being actuated so as to carry the cable away from the cutting edge of the blade.

Referringnow more,particularly to the drawings, for illustrative purposes; the cutter of ,the present invention is shown as comprising a frame structure, as generally indicated at 10, .as being. of generally rectangular configuration. This frame. is cast o r otherwise formed, from suitable metal or other material and internally cutout to receive a levermemben 11 having integrallyformed angularly extending arm portions 12 and 13, ,asshown most clearly in Fig. 5. The lever member 11" is pivoted as at 14 at the armjunctures so that the lever member may beoscillated with a swinging movement.

The arm 12 extends across one endpf the frame structure, while the arm 11 extends-generally .along ;a side edge of the frame and-is provided with alaterally; pro: i s p on wh ch p i c ahe ad t a c a edge of; the ;f rg4ne .-structure and forms a digitallyem gageablez-partwhich permits the arm-13 to be depressed against ascompression spring 16. 1 v g,

.As a'lsoyshown in Fig. 5,-the framestructureis provided with a longitudinally, extending2 bore .17,;within which there is mounted; La -differentially adjustable screw consisting. of an elongate-member 18 :which has, an inner .end 19 in threaded engagement.withcompanionthreads 20 1formed in' the associated wall of the bore 17. The other end;.of themember 18- projectslfromz-zthenframe structure and may berknurled as shown-at 21in Fig-1 so as to facilitate rotationlofthe member. '3 'zmwu Referring again to-Fig. 5,zrthe"innermost end ot the member 18 is provided-with a threaded axially extending recess 22 within which there is a threaded stem.23 which is secured to a cutting blade 24' positioned ina-rectangurlar cross-sectional portion of 'the bore' for-reciprocable movement therein. The outer end of the blade '24 is bevelled to provide acutting edge 25 which is positioned below the outer end of -the arm-portion 12.

As will be seen most clearly from Figs. 4 and 6, the outer end of the arm- 12' carries an integrally formed tubular bushing 26 having a cable receiving bore 27-at one end. This bore extends at right angles to the cutting edge of the blade 24 and has its upper portion in registra tion with an arcuate groove 28 of the bushing which' extends across the cutting edge 25, as shown in Fig. 6,

' and forms an anviLsurface against which the cable-periphery will be pressed on one side by the' initial engaging action of the cutting blade, when the cable as indi cated at 31 is carried into a cutting position against the cutting edge 25 by the action of the compression spring 16.

The cutting operation is' completed by rotating the frame structure 10 circumferentially around the cable axis by means of a small handle 32 which is mounted in a position projecting from one surface of the frame structure. Rotation of the frame structure causes the cutting edge to cut into the outer layer or layers of the cable to a depth which will be limited by the engagement of surfaces 29 and 30, on opposite sides of the blade, with the exposed layer surface as the blade is carried circumferentially around the cable. Thus a concentric cut will be produced and the coaction of the surfaces 28, 29 and 30 will maintain the cable in a straight condition with the result that the cutting depth will be maintained extremely accurate.

At the conclusion of the cutting operation, the tubular bushing may be swung away from the cutting blade, carrying the cable with it, merely by depressing the por- .tion .15 with the thumb or finger. With the bushingpositioned away from 'the'cutting blade, the cable may be withdrawn and inserted with ease without interference from the cutting blade.

Referring ,to Fig. l, a side face of the framestructure Ill-is provided'with a cut out notch or window 33 which isprovided along one edge with graduations 34 which cooperate with other graduations as indicated at 35 on the outside of the member 18 associated witha locus line 36, whereby the'micro-positioning of the cutting edge of the 'blade may be accurately accomplished merely by turning the knurled end 21 in the proper direction.

.A further convenience to enable cutting a desired length of insulation or other covering at the end of-the cable is provided for by placing a graduated scale, as indicated at 37 on the side face of the 'frame structure, this scale being graduated in proportional parts of an inch, and so positioned that if a cable isplaced over the scale with the cable end at the desired length to be removed, by placing the thumb at the adjacent end edge of the frame structure 'and holding the cable at this point, the desired length of covering will be removed when the cable is inserted through the bushing up to the point marked by the-thumb.

As will be seen from Figs. 6 and 7, the bore 27 of the bushing may-be considerably larger than the cable which is 'inserted'therein. However, due to the arcuate construction of the groove 28 and the registering portion of the bore 27, the cable in cutting position will always be moved to the top center of the groove28, as seen in Fig. 5, irrespective of the size of the cable inserted through the bore .27. -The ca'ble is further guided to the top center-of. -'groove 28, as explained -above,'by the ac- 'tion of a substantially V-shaped'notch 38 formed in the frame structure and positioned .on one side of the blade, as shown in Figs. 3 and 6. This isa very important :featurein'thatit eliminates uncertainty and permits a high degree of accuracy since the cable is always properly positioned in the cutting operation.

Various modifications may suggest themselves to those Skilled in .the art without departing from the spirit of myinvention, and, hence, -I do'not wish to be restricted to the specific form shown or uses mentioned, except to the extent indicated in the appended claims.

I claim:

.1. A cable and wire covering cutter, comprising: a frame; a blade .supported .on said frame having a straight cutting edge; flat abutmentsurfaces carried by said frame on opposite sides of said cutting edge; means for adjust ingsaid blade to position said cutting edge with respect to;said abutment surfaces to determine the cutting depth; a :bushing swingably supported on said frame having a cablereceiving opening and including an elongate arcuate surface having a longitudinal axis extending across said blade and abutment surfaces, said support being so arranged that swinging movement of said bushing will be in a direction to maintain the longitudinal axis of said arcuate surface in parallel relation to the axis of a cable :in said bushing and to :said abutmentsurfaces; and spring means for normally biasing said bushing in a direction to carry the cable covering into engagement with said cutting edge and said abutment surfaces, whereby said cable is pressed against said arcuate surface and laterally centered thereon at the cutting position, said frame and cable being relatively rotatable to cut the covering throughout its circumference.

2. A cable and wire covering cutter according to claim l, in' Which'the cable receiving opening and arcuate surface have radii of gyration appreciably greater than the radius of vgyration of the cable surface to be inserted therein.

3. A cable and wire covering cutter, comprising: a

substantially rectangular frame structure having a longitudinally extending passage therein; a cutting blade in said passage, said blade having an outer end formed into a cutting edge positioned adjacent one end surface of said frame structure; a differently adjustable support for said blade in said passage including a digitally operable member projecting from an opposite end surface of said frame structure,-whereby said blade may be longitudinally moved endwise to adjustablyposition-said cutting edge for different cutting depths; a'lever member pivoted between its ends adjacent a corner of said frame structure for swinging movement, said lever having integrally formed angularly extending arms, one'ofsaid arms extending along and projecting from aside of said frame structure, and the other of said arms extendingalong said first mentioned one end of said frame structure, and including a transversally extending-cable receiving opening therein positioned to support the cable over the adjacent cutting edge' of said blade; and spring means normally acting to bias said lever member in a direction-to'carry the cable in said opening to a cutting position :against said cutting edge, whereas manually applied pressure against said one of said arms carries the cable out of the cutting position. A 4. A cable and wire covering cutter according to claim 3, wherein a projecting handle extends from the frame structure adjacent said opposite end of the structure, by which the structure may be rotated around :the cable to circumferentiallycut the covering thereof'throughout its circumference.

References Cited in the file of this patent UNITED STATES PATENTS 2,317,944 Schaefer Apr. 27, 1943 2,385,368 Montgomery Sept. 25, 1945 2,388,698 Montgomery Nov. 13, 1945 2,437,514 Givens Mar. 9, 1998 2,442,063 Stone May 25, M48 2,683,930 Walters June 20, 1954 2,752,676 Trickle July 3, 1956 FOREIGN PATENTS 257,550 Switzerland Apr. 1, 1945 

